Bob Diamond's role shows investment bankers are on the rise again

The backlash over the new Barclays chief has begun. How could an investment banker – the risk-takers blamed for the financial crisis – be trusted with such an important job?

Two years ago investment bankers were pictured leaving Canary Wharf carrying their possessions after Lehman's collapse. Today, the City's best-known investment banker is appointed chief of Barclays Photograph: Rex Features

Two years ago next week marks the anniversary of the collapse of Lehman Brothers. Then the image of investment bankers was of legions of them trudging out of offices in Wall Street and Canary Wharf with their heads hung low, carrying brown boxes full of their possessions.

How the picture has changed with the appointment today of Bob Diamond, the highest-profile investment banker in the City, as the chief executive of Barclays. The American-born 59-year-old is the epitome of a Master of the Universe. Sharply dressed with sparkling shoes and bright white teeth, Diamond has built an investment bank at Barclays that is now so large that it generates more than 80% of the profits at a bank that is still best known for its high street banking operation.

The backlash has already begun. How could an investment banker – one of the breed of risk-takers blamed for tipping the developed world into financial crisis and recession – be trusted enough to win the appointment to such a prestigious job?

While the bank will see the criticism as all too predictable, the unions were among the first today to raise their concerns in stinging fashion. Paul Kenny, GMB general secretary, said: "These are the bankers who caused the recession sticking two fingers up at the taxpayers who rescued them. This is about as insulting and divisive as it gets."

While Barclays will argue it survived without direct injections of taxpayer cash, it cannot dispute that it has benefited from the billions of pounds thrown at the sector to keep it afloat. Neither could it dispute that its growth has been fuelled by Lehman's demise. Diamond and Barclays tried to buy Lehman in the hours before it collapsed in September 2008. It ended up buying the part it really wanted – the Wall Street businesses – out of the ashes of Lehman's catastrophic collapse and in the process turned itself into a powerhouse in the investment banking world.

Barely two years on, another investment banker is being discussed as a potential boss for another major UK bank – HSBC. Even before the HSBC chairman Stephen Green was being lined up to become trade minister the talk in the City was that Stuart Gulliver, the highest earner at HSBC and head of its investment bank, was being groomed as the next chief executive.

The City was quick to bounce back in the wake of the multibillion bailout of the banking sector. The phrase "bonuses are back" echoed around the Square Mile even as, in the real world, dole queues were lengthening and the belts of non-bankers were being tightened.

Investment bankers, it seems, are hard to keep down – even when governments are demanding greater disclosure on pay and threatening to force them to break off from their retail banking parents.